Can testing your sense of smell predict memory decline and dementia?

Two studies have looked into how smell and dementia risk might be linked, but could it really be used as a useful indicator?

The latest research to come out of the Alzheimer’s Association International Conference in Toronto has linked a declining sense of smell with cognitive impairment.

Researchers compared how your sense of smell changes with two well-established characteristics of dementia – the size of the brain area that’s involved in memory, and the amount of amyloid proteins.

Testing the sense of smell in 397 older people without dementia, researchers from Columbia University Medical Centre used the University of Pennsylvania Smell Identification Test (UPSIT) to see if it could predict cognitive decline by checking for thinning of the entorhinal cortex, an area of the brain linked to memory.

During the four-year research period, 50 people developed dementia, and an impaired sense of smell were both significantly associated with developing dementia.

Similarly, in the second study, also conducted at Columbia, researchers measured the amount of amyloid proteins in the brain and tested UPSIT scores, and found those with an impaired sense of smell were three times more likely to have memory problems.

Dr Doug Brown, Director of Research and Development at Alzheimer’s Society, said:

‘These studies add to growing evidence that sense of smell can be affected in the early stages of dementia. However, there are many reasons why people might lose their sense of smell – the natural ageing process, some medications, and more than 60 medical conditions can all affect someone’s ability to sniff out certain smells.

‘While less invasive tests for dementia would be incredibly useful, we need larger studies to test how reliably sense of smell can be used as an early predictor of memory decline and dementia.

‘Most people experience some sensory loss as they age, so anyone with an impaired sense of smell shouldn’t be immediately worried about dementia, but if you have noticed changes to your sense of smell at any age, it's advisable to speak to your GP.’

If you’re worried about memory problems, it’s definitely worth seeing your doctor. Click here for more early signs of cognitive impairment and dementia.